Ocular and oculocutaneous pigment defects in man and animal homologues are investigated for their clinical, ophthalmologic, biochemical, ultrastructural, genetic, epidemiologic and pleiotropic features to determine the biochemical or morphologic basis of these defects with the final objective of seeking therapeutic or other means of ameliorating, treating or preventing these disorders. Among the pleiotropic effects common to the oculocutaneous disorders to be studied are the abnormal routings of the optic and possibly optic neuronal tracts that are associated with a lack of pigment in fundus and inner ear respectively. Mechanisms which may be defective in some forms of albinism will be investigated by testing the cells for B adrenergic and hormone receptor sites, the influence of calcium flux on tyrosinase and melanin, and the protein and lipid content of melanosomes in pigmented and various mutant strains of mice. Studies to identify the abnormal inclusions in YM and HPS cells are presented. Linkage studies for YM, HPS, and various African albino types will be done to determine genetic homology. The pathogenesis of skin cancer and the corresponding development of chromosomal abnormalities will be studied in Africa. Heterozygote detection tests will be developed.